The above type arrangements are provided in fine scales in which the stopping and releasing steps occur frequently and fast or are repeated, in order to protect the very sensitive knife edges when the load is dropped on the pan or platform. It has been customary in order to protect the knife edges to remove the scale beam from its support in order to affect its locking or stopping and thereby the load or end and the middle or main knife edges become unloaded. For weighing, that is when the releasing is performed, the middle edge is lowered on its support and the end edge support is lowered onto the end edge.
If such lowering was taking place too fast, then the knife edges could become damaged leading to inaccuracy in later weighings.
In order to prevent the above, motorized lowering arrangement came into being which provided a constant lowering speed, independent of the operator, for the knife edges and the platform. Such arrangements required a large and complex apparatus, therefore, they are expensive and do not reliably prevent a hard lowering of the knife edges and the platform onto each other, especially during variation in the power supply.
For the controlling of the lowering speed also pneumatic dampers become known. Such dampers have the disadvantage that they require the compression of the air and sometimes the damping is so weak that transmission levers are required for the amplification of the damping.